Design Engineers Take On Component Police

Design engineers want to use parts that work. Component engineers and purchasing agents want as few parts as possible. Put the two together, and trouble ensues.

Preferred vendors can be a problem. The purchasing people have their favorites, and the engineer may not always get the desired part. I had requested some optical patch cords from a certain vendor; purchasing went with a different vendor who had supplied copper cables in the past. One of the fiber cables still had the unpolished end fiber sticking out of the connector -- so much for quality control.

A similar quality problem occurred when I specified a certain brand of twisted-pair cable for a production test fixture. My own test fixture worked nicely with the brand I chose, but production was swayed by purchasing to go with its preferred brand. There was a huge variation in attenuation between pairs in the same cable. Let the losses begin.

Sometimes, you can't get parts with multiple sources, or even a second source. Trying to explain to the components group that a certain brand of optical transmitter and receiver was the only one available at a reasonable price did not stop them from whining -- until they did some of their own research and determined that there really was no choice.

I did see their point, especially when that same vendor made a process change that resulted in a horrendous optical overshoot in the transmitter. I had to come up with a fix that required a large value trimmer capacitor, and because the value I needed was a year lead-time (after I bought about 400 of them myself), purchasing wouldn't allow it. We ended up using a varactor diode and a trimpot instead.

The most difficult component hassle was with a simple 32.768kHz crystal and the associated CD4060B CMOS oscillator/timer IC. No way were the component cops going to allow something as obsolete as the CMOS 4000 series in a new design! It took a lot of explaining that, old or not, it was not about to go obsolete and that the chip had recently been made available in a surface mount package. I was certainly not about to design in a separate crystal oscillator and counter chain.

The crystal itself was another problem. What's so hard about procuring a 32.768kHz tuning-fork crystal that is made in the billions? None, except for the fact that the corporate-preferred vendor had none in stock and there would be a twelve month lead time. I sent a "nastygram" to the entire department explaining that I could not sit around for a year and that the component police needed to find and approve a crystal now. They did.

Have you ever been a component engineer? Let's hear your side of the story.

At Northern Telecom everybody hated the Components Engineering department. But I saw many times where they would assist and educate a young and green engineer who didn't understand how to specify components.

One of my favourites was when the quartz-crystal engineer had to educate some designers that crystal load capacitances were standardized and they couldn't just pick any value they liked.

Another time a colleague had to have a resistor go through the full qualification process, lasting several months. While that resistor family was widely used in the company that *value* had never been used before. He was told they couldn't expidite the process.

When Nortel started to collapse, Components Engineering were one of the first groups to be cut. High management figured that function could be performed by the contract manufacturers then being brought in. Bad mistake on top of another, and everyone knows the company's end result.

Overall cost of component (initial price, long term price trending, quality, defect rate, short and long term availability, toxicity, ease of use, end of life terms, alternate sources that are form, fit & function compliant, agency approvals, industy standard, etc..).

Does the component lifecycle match your product life? Does the manufacturer discontinue almost as many components as they release?

Online avalability of comprehensive component information, complete part number, data sheet, package dimensions, tape and reel dwg, pricing, inventory, sample ordering, lifecycle, levels of information provided that does not necessitate a call or email to manufactuer that is diverted to voicemail or answered by automated email away message.

My favorite manufacturer is those that meet all of the above and tries to understand the customer products and personalties, provide appropriate product information in a passive, effective manner, does not hound via phone calls, spam, unplanned visits. Does not feel the need to provide cheap pens that require 110 lbs of pressure to expel ink or conversely leak, various sizes of calenders, and other personalized landfill garbage from China.

You take an adversarial approach. What you call "Component Police" is actually just using good design practice while noticing that the product has to ship. "Favored Vendors" are the ones who deliver product to production in time to meet customer requirements. It also helps to be cost effective so we can pay overheads including ourselves.

I once looked at switching a diode package which would help design for manufacture. It turned out the desired component which was an industry standard was 26 weeks lead time when we had 250K of the other in stock. I did not change it and kept my friends in purchasing and logistics still as friends.